Zurich,Dec12:Regular rail service through the world’s longest tunnel has begun, carrying passengers deep under the Swiss Alps from Zurich to Lugano.

The famed Gotthard Base tunnel (GBT) was given a ceremonial opening in June, attracting European leaders including the German chancellor, Angela Merkel, and the French president, François Hollande, for its first ride.

Sunday marked the start of normal commercial traffic through the 35-mile (57km) GBT, which took 17 years to build, at a cost of over 12bn Swiss francs (£9.3bn).

The Swiss news agency ATS reported that the first regular passenger train to use the GBT pulled out of Zurich at 6.09am (0509 GMT) and arrived in Lugano at 8.17am, with the tunnel passage shaving 30 minutes off the previous travel time.

“It’s Christmas,” Andreas Meyer, the chief of the Swiss national rail service, SBB, was quoted as saying by ATS after the journey was over.

The ambitious GBT project has been praised across Europe for its pioneering efforts to improve connectivity from Rotterdam to the Adriatic.

The Swiss-funded tunnel was largely made possible by technical advances in tunnel-boring machines, which replaced the costly and dangerous blast-and-drill method.

The GBT has surpassed Japan’s 33.4-mile (53.9km) Seikan tunnel as the world’s longest train tunnel. The 31-mile (50.5km) Channel tunnel connecting Britain and France has been bumped into third place.